Or polishing device



. o. E. GRAHAM. l f. y BUFFING-OR POLISHING DEVICE,

No. 604,933. w

Patented May 31,1898..y

I y UNITED, STATS'f 'PATENT OFFICE;

cuARLESE.v Gazing-non SwnMPScoTT, MASSACHUSETTS, ASSIGNOR To :'GEORGE1H- i?. `Ifmiccr,"TRUSTEE,- oF BOSTON, MASSACHUSETTS,

" 1 i srncrrtca'flronromsngpart of utters Patent No. 604,933, dated my s1, 189s.A

TodZZ whom/ Lt y111,014/"cortcerjt: vi Beit known that I, CHARLES E. Gaannmbf Swampscott, inthe county of Essex and State and useful Improvements lin Buing or Polishing. Devices, of which Athe following'is av specification.

. 4faced cylindrical cushion or roll which is [O wholexconstitutinga rotary bulng device or rotary polishing device. An appliance of vthis character is shown in Letters Patent of the United Stateslo.V 590,714, v'dated September 28,1891??uw A. 'lh'e 'present in'vention'has for its object to provide a centrifugally-.maintained yieldingsurfaced-cylindrical cushion or rollwhich shallhavewhen inoperation a true cylindrical 'surface Tof' a uniform predetermined diameter and shalljalso have a yielding quality independent-of the centrifugally-.aetuated portionof the cushion or, in other words,shall a 5 have interposed between the working'cover and th centrifugally-actuated portion of the i cushion abedlv for `said cover which will pre'-- vent the distortion of-the cushion by centrifugal force' and willalso prevent the outeredge ofthe cover from forming an undesirable shoulder or .projection on the 'periphery of -therolL M 'y inventioncousists in the improvements whiehI-.willnow proceedtodescribeandelaim.

` Of the accompanying drawings,- forming a part 'of this specification, Figure 1 represents'v a partialside elevation andfpartial longitu?3 dinal sctionof Vajroller cylinder embodying L fmy'inventiom; Fig; 2 represents a section oniiticnswhle theirouter portions are discontional view of one of the'sections of the yields" i or' holderofitheyielding cushion, saidhub being --liere' shown :asia `tube 4adapted to be onf thefsliaftwhieh rotates the appli- .ance of-which thefcfushion'Y forms a of' Massaehusetts', have invented certain'new This invention relates to a *yielding-sursupported by a. rotary .hub or holder and supvports aiiexible bander 'working cover, the

part"y The 59 hubispreferablygprovided at itsiends with .suitable Ymearni forgrasping andi-supporting 1 'Applicationlilled December 6,1897., Seal-No..660,846. (No model-l the" ends of a iexible working cover @which `may be a sheet of sand or emery paper, the same meansbeing here shown that are set forth in Letters Patent ofthe United States No. 550,062--namely, collars gg, of felt or hub,adclampingfngers h, which project portions of the cover, pressing the latter into these particular devices and may be used in connection with any other suitable means for z connecting the' end portions of the working cover with the hub'al or,without such means.

The hub is provided -with a ceutrifugallymaintained yielding cushion, here shown as composed of a Series of annular flexible or Ylimp sections strung upon the hub a, their Itisfessentiathatthe sections-be spaced or separated-to give thel bearing edge of each some extent, this .freedom also'enabling the hub.A v' i Each section may' be composed of two or more annular flexible disks or members 3 3, said members being cemented or otherwise firmly `secured together at their inner por- J"neeted and separable.

are preferably rings or washers of leatherboard or other comparatively stiff material,

tions thus constructed Yare adapted to beas-A any desired length, the cushion" being made creasing the number of sections.

fover. the perpheries ofsaid collars and are, adjustably connected with the hub, so that' 'they maybe forced inwardly upon the end `the yielding surfaces of the collars g. My

present improvements are not dependent on t v'bearing Vedges tosink inwardly toward the one `of 'these `being preferably cemented or otherwise secured to each section. The-see-v sembled upon the hub to form a cushion ofA other suitable yielding materal,aflixed to the euter edges constituting a series of flexible or limp 'cover-bearings surrounding the hub section freedom to swayor'bend sidewise' to Tosec'ure adequate spacing between the 1 sections, 'spacing-pieces 4 are provided, which IOO more or 'less yielding by decreasing or inbearing edges of the sections are yieldingly `threads being preferably of cotton.

quired toincrease the diameter of the sheath.

held by centrifugal force at their maximum distance from the axis of rotation. The spaces between the sections permit the bearing edges to sink under the pressure of the worlr against the working cover b su lliciently to conform to the inequalities and curves of thework. 'f The construction above described is practically the same as that set forth in Letters Paten-t No. 500,714,.above referred to..

Heretofore the working cover b has been=i-n direct contact with the marginsof the disks. When the roll is rotated at a high rate of speed,- the edges of the disks become the equivalent of springs,which while adapted to yield inwardly are pressed outwardly with considerable force. This outward pressure sometimes causes distortion of the rollbe cause the loose or more yielding portions of the edges ot the disk's`are forced outwardly farther than the firmer portions. The outward pressure also causes the overlapping end of the, cover b to form an objectionable shoulder on the cover by preventing the inward sinking of said end and of the end which it overlaps. l'Io overcome these objections is the chief object of my invention, and to this end I interpose between the centrifugallymaintained cushion and the working coverb 'a seamless tubular woven sheath s, which incloses the cushion and is laterally inelastic, or, in other words, is not capable of stretching in the direction required to increase its diameter, so that the edges of the disks are- `prevented from being forced outwardly beyond the internal diameter of the sheath..v The fabric of which said sheath is made is, l however, compressible and of such thickness| that i-t forms a bed for-the'working cover which is. suficiently yielding to permit the overlapping edge of the cover b and the edge which it overlaps to sink inwardly, as shown in Fig. 2, and thus prevent the formation of a projecting shoulder.v

The seamless tubular woven. fabric of the sheath is preferably similar to ordinary tubular wicking for lampsythe warp and weft The lateral inelasticity of the sheath or its freedom liability to stretch in the direction reisamimportant feature,this quality preventing the fabric from being stretched by the outward' pressure of the centrifugally-maintained cushion against it, and thus permit- 'ting the distortion o! the cushion, and from losing the compressibility necessary to permit the sinking of the edges of the working cover. The seamless construction of.' the sheath is also important, because the sheath is thereby caused to present a surface which is uniformly compressible at all points and free from-a relatively hard ridge orline which would necessarily be presented if two edges of a covering-piece were united to form a seam or joint. In an appliance of this character such a seam'or joint would be very objectionable and would prevent thework from being uniformly bued or finished, the relatively hard part at the seam giving a harder pressure on the work than the other portions. The predetermined diameter of? the sheath should besuch that the sheath will be lled and held in a plump condition4 by the cushion when the latter is centrifugally distended,

it yields with the cushion to the pressure of the article yapplied to the cover.

The sheath may beheld in lace om the cushion by the fingers h, whic securethe working cover. I prefer to cover the ends of the sheath with finishing-caps s, preferably ot 1eather,.cemented tothe ends of the sheath and turned inwardly beyond said ends and clamped betweenl the collars g andthe plates or heads h', in which the fingers h are guided.

It is obvious that myimprovement may be applied toa centrifugally-maintained cushion of any other suitable construction.

I claim- 1. Au appliance of the character specified, comprising a rotary hub, a yielding cushion secured to-said hub and adapted to be centrifuga-lly maintained,and a seamless tubularlatorally-inelastic sheath of fibrous material havi-ng a compressible body ineiosing said cushion and forming a yielding bed for a workin g fcover.

2. An appliance of the character specified, comprising a rotary hub, a cushion composed of limp annularsections surrounding the-hub aand closely confined at their inner portions around the-hub,.their outer portions being free fte-yield, and a seamless tubular laterally-inelastic sheath of fibrous material having a f compressible body ineiosing said cushion and forming a yielding bed for a working cover.. 5 lin testimony whereof I have signed my fname to. this specification, in the presence of Aetwo subscribing witnesses, this 23d day of jNovember, A. D. 1897.

, L oHARLEsEgGRAHAM.'

Witnesses.: 4- C. F. BROWN,l

A. D. Hmxson.

the flexibility of the sheath being suchf'that v IOO IIO 

